Venting closure



g- 1964 o. D. PUSE ETAL VENTING CLOSURE Filed Dec. 10, 1962 FIG.

FIG.

INVENTORS OWEN D. PUSE a; RALPH H. WHITN Y Ig Us 1Q 'a fommzvs UnitedStates Patent 3,144,154 VENTING CLOSURE Owen D. Puse, Toledo, Ohio, andRalph H. Whitney,

Glasshoro, N..l., assignors to Owens-Illinois Glass Company, acorporation of Ohio Filed Dec. 10, 1962, Ser. No. 243,535 Claims. (Cl.215--56) This invention relates generally to a venting closure for acontainer and more particularly to a closure-container combination whichwill control the amount of pressure build-up in the container.

Although venting closures are generally old in the closure-containerart, none of the venting closures disclosed to date have been able tocontrol the amount of pressure which is permitted to build up within thecontainer before excess pressure is released. The present inventionprovides a closure which may be designed to accurately control theamount of internal pressure which is permitted to build up within acontainer.

Accordingly, it is an object of this invention to provide aclosure-container combination having venting means controlled by thepressure build-up within the container.

It is another object of this invention to provide a closure adapted toaccurately control the amount of pressure build-up within a container.

Other objects and advantages of this invention will become apparent fromthe following description taken in conjunction with the annexed sheet ofdrawings on which:

FIGURE 1 is a sectional elevational view of a closurecontainercombination of the present invention and showing the container as havinga sutlicient build-up of internal pressure to permit operation of theventing means;

FIGURE 2 is a bottom plan view of the closure of the present invention;and

FIGURE 3 is a fragmentary sectional view of the closureeontainercombination of the present invention illustrating the relationship ofthe parts when the pressure within the container is substantially atatmospheric level.

In brief, this invention comprises a closure in combination with acontainer having a neck portion terminating in an annular rim definingthe periphery of an open mouth. Externally disposed of the rim is anannular step shoulder which forms a bearing surface in a plane lowerthan that defined by the rim. The closure is adapted to engage the neckof such container and has a resilient top panel portion and an annularskirt formed integral therewith. The skirt extends slightly above thetop panel to form an annular raised portion. In the included angle atthe juncture of the skirt and the top panel, there is provided anannular convex sealing shoulder which engages the annular step shoulderof the container neck when the closure is secured to such neck. At leastone, and preferably a plurality of, vent slots extend radially acrossthe annular convex sealing shoulder. Any desired means, such as screwthreads may be provided for securing the closure to the neck of thecontainer. The relative dimensions of the closure and the neck of thecontainer are such that when the closure is secured to the neck of thecontainer with the annular convex surface engaging the annular stepshoulder, the underneath surface of the top panel will be in sealingengagement with the annular rim of the neck, provided there is nosubstantial pressure within the sealed container. When the pressurewithin the container builds up to a sufliciently high degree, it causesthe resilient top panel to be lifted out of engagement with the annularrim thereby permitting the excess gas to flow to and out through thevents in the annular convex sealing shoulder.

Referring now to the drawings, there is shown in FIG- URE 1 a containerhaving a neck 12 on the outside portion of which are formed threads 14which extend upwardly and terminate near the open .mouth thereof. Theopen mouth of the container is defined by an annular rim 16. Between therim 16 and the upper reach of the threads 14, the surface of the bottleflares outwardly and downwardly to form an annular shoulder 18.

There is provided a closure 20 having a resilient top panel 22 and anannular skirt 24 integrally formed therewith. The annular skirt 24extends above the top panel 22 to form an annular raised portion 28.Threads 26 are formed on the inside surface of the skirt 24 and matinglyengage the threads 14 of the neck 12. There is provided an annularconvex sealing shoulder 30 at the included angle or internal corner ofthe junction between the top panel 22 and the skirt 24. The annularconvex sealing shoulder 30 engages the annular step shoulder 18 of theneck 12 when the closure is secured thereto. The distance measuredaxially of the container between the top of the rim 16 and a point onthe annular step shoulder 18 is at least as great as the distancebetween the underneath surface of the top panel 22 and a correspondingpoint on the annular convex sealing shoulder 30. As a result when theclosure 20 is initially secured to the container 10 and the interior ofthe container is substantially at atmospheric pressure, the underneathsurface of the top panel 22 will sealingly engage the annular rim 16 ofthe neck 12. As the internal pressure within the container builds up,due to emission of gases by the product contained therein or elevatedstorage temperatures, the resilient top panel 22 will be lifted out ofsealing engagement with the annular rim 16. To permit the escape ofthese pressurized gases, there are provided vent slots 32 which extendradially across the annular convex sealing shoulder. The gases escapethrough these vent slots 32 and then through the open area between therespective threads 14 and 26. By virtue of the raised portion 28 of theskirt 24 the venting means are permitted to function even though otherarticles are stacked upon the sealed container.

In many cases, it is desirable that a certain amount of internalpressure be retained in the sealed container. The amount of pressuredesired depends upon the type of goods which are packaged within thecontainer as well as upon the type of material used to form thecontainer. For example, if a thin walled plastic container is used topackage the goods, a relatively small amount of pressure build-up willcause the bottom of such container to bulge outwardly thereby producinga so-called rocker bottom effect. For this type container, a closurewhich releases the pressure after a relatively small buildup ispreferable. If a glass container is used to package the goods a somewhathigher pressure build-up is acceptable. However, even with glass thepressure build-up must not be permitted to become excessive or danger ofrupturing the bottle is presented. For this type container, a closurewhich permits a reasonable amount of pressure build-up may be desirable.If a plastisol coated glass container is used even higher pressures maybe permitted and accordingly a closure which permits a high build-up ofpressure may be used.

Numerous factors may be varied when forming a closure of the presentinvention to provide one which will permit pressure release at anydesired level. Thus, the resilience of top panel 22 may be varied eitherthrough the use of different types of material to form the closure or byvarying the thickness of the top panel. For example, low densitypolyethylene is considerably more pliable and thus more easily flexedthan is high density polyethylene. Accordingly, if all other factors areequal, the top panel of a closure formed from low density polyethylenewould be raised off of the annular rim of the neck at a lower pressurethan would the top panel of a closure formed from high densitypolyethylene.

Similarly, for closures formed with like materials, the thicker the toppanel, the greater will be the pressure required to raise the panel.

Another factor which may be varied in order to vary the amount ofpressure required to put the venting means into operation is thedistance, measured axially of the container, between the lowerunderneath surface of the top panel 22 and a point on the annular convexsealing shoulder 30. For example, if such distance were reduced, theunderneath surface of the top panel 22 would engage the rim 16 of thecontainer before the annular convex sealing shoulder 30 engaged theannular step shoulder 18 of the container. Continued screwing of theclosure 20 to effect an engagement of the respective shoulder portions18 and 30 would then cause the annular rim 16 to flex the top panel 22outwardly. It is quite obvious that all other factors being equal, themore the top panel 22 is flexed upwardly by the initial securing of theclosure on the container, the greater will be the internal pressurerequired to put the venting means into operation.

Still another factor which may be varied is the length of the lever asmeasured by the radial distance between the point of engagement of thetop panel and the annular rim and the juncture of the top panel and theskirt. Thus, the shorter the distance between these two points, thegreater will be the pressure required to raise the top panel out ofsealing engagement with the annular rim 16 to thereby put the ventingmeans into operation.

It will be readily apparent to those skilled in the art that the presentinvention provides an economical closure which permits venting at anydesired predetermined pressure level. Further, by providing the skirtwith an annular raised portion extending above the top panel, theventing means is permitted to function even though other objects arestacked upon the sealed container.

It is obvious that many changes and modifications may be made in theclosure container combination of the present invention without departingfrom its spirit and scope which is to be limited only by the followingclaims.

We claim: 1. The combination of a container having a neck por- .tionterminating with an annular rim defining the periphvent slot therein andadapted to engage the annular step shoulder of said neck portion whenthe closure is secured thereto, the sizes of the respective portions soproportioned that when the closure is secured to the neck of thecontainer and the pressure in the container is substantiallyatmospheric, the undersurface of the resilient top panel will sealinglyengage the rim of said neck; and means for securing the closure to saidneck.

2. The combination as defined in claim 1, wherein there is provided anannular raised portion formed integral with said skirt and extendingabove said top panel.

3. The combination of a container having a threaded neck portionterminating with an annular rim defining the periphery of an open mouthand having an externally disposed annular step shoulder forming abearing surface in a plane lower than that defined by said rim; and aclosure comprising a resilient top panel and an annular skirt formedintegral therewith, said skirt being formed with threads on the insidesurface thereof, an annular convex surface above said threads in theincluded angle at the juncture of the skirt and the top panel, saidannular convex surface having at least one vent slot extending radiallythereof and adapted to engage said annular step shoulder'when theclosure is secured to said neck, the axial distance between a point onthe annular step shoulder and the rim being at least as great as thedistance between a corresponding point on the annular convex surface andthe underneath surface of said top panel.

4. The combination as ,definedin claim 3, wherein there is providedanannular raised portion formed integral with said skirt and extendingabove said top panel.

5. The combination of a container having a threaded neck portionterminating with an annular rim defining the periphery of an open mouthand having an externally disposed annular step shoulder forming abearing surface in a plane lower than that defined by said rim; and aclosure comprising a resilient top panel and an annular skirt formedintegrally therewith, said skirt being formed with threadson the insidesurface thereof, an annular convex surface above said threads in theincluded angle at the juncture of the skirt and the top panel, saidannular convex surface having at least one vent slot extending radiallythereof and adapted to engage said annular step shoulder when theclosure is in full rotatable engagement with said neck, the axialdistance between a point on the annular step shoulder and the rim beinggreater than the distance between a corresponding point on the annularconvex surface and the underneath surface of said top panel whereby thepressure at which venting will occur may be varied by rotating theclosure on said container neck between a position where said top panelinitially engages said annular rim and said full rotatable positionwhere the annular convex surface engages the annular step shoulder.

References Cited in the file of this patent UNITED STATES PATENTS

3. THE COMBINATION OF A CONTAINER HAVING A THREADED NECK PORTIONTERMINATING WITH AN ANNULAR RIM DEFINING THE PERIPHERY OF AN OPEN MOUTHAND HAVING AN EXTERNALLY DISPOSED ANNULAR STEP SHOULDER FORMING ABEARING SURFACE IN A PLANE LOWER THAN THAT DEFINED BY SAID RIM; AND ACLOSURE COMPRISING A RESILIENT TOP PANEL AND AN ANNULAR SKIRT FORMEDINTEGRAL THEREWITH, SAID SKIRT BEING FORMED WITH THREADS ON THE INSIDESURFACE THEREOF, AN ANNULAR CONVEX SURFACE ABOVE SAID THREADS IN THEINCLUDED ANGLE AT THE JUNCTURE OF THE SKIRT AND THE TOP PANEL, SAIDANNULAR CONVEX SURFACE HAVING AT LEAST ONE VENT SLOT EXTENDING RADIALLYTHEREOF AND ADAPTED TO ENGAGE SAID ANNULAR STEP SHOULDER WHEN THECLOSURE IS SECURED TO SAID NECK, THE AXIAL DISTANCE BETWEEN A POINT ONTHE ANNULAR STEP SHOULDER AND THE RIM BEING AT LEAST AS GREAT AS THEDISTANCE BETWEEN A CORRESPONDING POINT ON THE ANNULAR CONVEX SURFACE ANDTHE UNDERNEATH SURFACE OF SAID TOP PANEL.